Year
2019
Abstract
For the effective and efficient implementation of international Safeguards it is essential that the Operator’s measurement system is maintained at a level of high quality and improved, as necessary. Besides the internal quality control, it is important to have elements of Quality Assurance (QA) in place. In general, intercomparison programs operated by international organizations form an essential element of external QA. However, there were no such inter-comparison programs with Plutonium samples available in Japan because of very few users and difficulties in the shipment of such samples from foreign laboratories. To cope with this situation, the IAEA, the Japan Nuclear Material Control Center (NMCC) and JAEA agreed to organize the intercomparison by using actual safeguards samples containing Plutonium and Uranium. Inspection samples, taken two from plutonium fuel facilities (JAEA-PFDC) and from two from reprocessing facilities (Tokai Reprocessing Plant, JAEA-TRP) are selected by the Inspectorates and prepared for shipment to the Safeguards laboratories together with other samples according to the normal treatment procedure. As such, the Safeguards laboratories receive and analyze them as inspection samples as well as intercomparison samples without additional cost for analysis or sample transportation. In recent years laboratories from facilities other than JAEA asked for participation in this program which has been accepted. Because these intercomparison samples are prepared from actual verification samples, they have no reference value and results of each participant are compared with the grand mean of all laboratories. However, the program is still beneficial in that it uses actual process materials and provides for a comparison to the results obtained by other laboratories. Laboratories can identify the bias or trend if any and deal with it as necessary. The practicality and effective use of this DA intercomparison, which is operated since more than 20 years, will be explained.